- In eliminate_item_equal(), we could end up in a situation where:
  = The multiple equality has a constant C1 (and so it is the "head item")
  = The join order was such that we've generated "sj_inner_table1=C1" equality,
    and now are looking to generate "sj_inner_table2_=..." equality. 
  When looking for what should be the other member of equality, we run

      Item *head_item= current_sjm? current_sjm_head: head;
  
  which sees current_sjm!=NULL, and takes current_sjm_head (which is NULL because 
  the constant C1 is the head for all cases).

- Fixed in a trivial way: take current_sjm_head if we don't have constant.

MWL#180: Merge bugfix from 5.2 to 5.3 codebase + really fix version from which mariadb supports binlog checksums.

If the value of the flag cond_false of an Item_equal object is
true then the print method must return the string '0'.

The third parameter in the call of make_cond_for_table() that
built the pushed condition containing only outer references
was incorrect. This condition appeared for the first time in
the patch fixing bug 729039.
  

MWL#180: merge fixes from 5.2-rpl + forgot to adjust revision from which checksums are supported when merging into 5.3-based tree.

 - Fix windows CMake build.
 - Merge some later test case fixes, to see if they solve the random rpl_checksum failure.

The bug was introduced by the patch that fixed bug 717577.

Patch backported:

bzr diff
'-rrevid:alfranio.correia@oracle.com-20101121143257-se3vpqus73l4mum0
..revid:luis.soares@oracle.com-20101124111752-9b8260bd1qak87hr'
--old=lp:mysql-server --new=lp:mysql-server

presumably neither TMP nor TEMP environment variable are set.

mysql-test/suite/funcs_1/r/storedproc.result:
  Fixed test failure
mysql-test/suite/funcs_1/t/storedproc.test:
  Fixed test failure
  (The error changed as syntax for alter changed with ALTER ONLINE)
storage/maria/ha_maria.cc:
  fixed compiler warning

Added ALTER ONLINE TABLE, which will give an error if the change can't be done 'instantly' (without a table copy)


mysql-test/r/alter_table_online.result:
  Test new feature
mysql-test/t/alter_table_online.test:
  Test new feature
sql/handler.cc:
  Added comment
sql/lex.h:
  Added ONLINE keyword
sql/mysql_priv.h:
  Added option to alter table to require online operation
sql/share/errmsg.txt:
  Added error message if ONLINE can't be done
sql/sql_lex.h:
  Added online option
sql/sql_parse.cc:
  Added online option to mysql_alter_table()
sql/sql_table.cc:
  Added test that gives error if table can't be done instantly when requsted to be online.
  Fixed wrong test if table includes a VARCHAR
  Fixed wrong (but unlikely) handling of error conditions in ALTER table
sql/sql_yacc.yy:
  Added ALTER ONLINE TABLE syntax
storage/maria/ha_maria.cc:
  Fixed bug where 'start_bulk_insert' used too small buffer if used with unknown number of rows

This makes it possible to do safe multi volume snapshots as long as one snapshots the volume with the transaction logs last.


include/mysql_com.h:
  Added REFRESH_CHECKPOINT
mysql-test/r/flush.result:
  Added test of new FLUSH TABLES syntax + calls to checkpoint_status handler calls
mysql-test/t/flush.test:
  Added test of new FLUSH TABLES syntax + calls to checkpoint_status handler calls
sql/handler.cc:
  Added code to call checkpoint_state for all handlertons that supports it
sql/handler.h:
  Added new checkpoint_state() handlerton call to temporarly disable checkpoints.
sql/lex.h:
  Added CHECKPOINT keyword
sql/sql_yacc.yy:
  Added support for FLUSH TABLES WITH READ LOCK AND DISABLE CHECKPOINT
storage/maria/ha_maria.cc:
  Added handlerton call to disable checkpoints.
storage/maria/ma_checkpoint.c:
  Don't do checkpoint if checkpoints are disabled.
storage/maria/ma_static.c:
  Added maria_checkpoint_disabled
storage/maria/maria_def.h:
  Added maria_checkpoint_disabled
storage/xtradb/handler/ha_innodb.cc:
  Added handlerton call to disable checkpoints.
storage/xtradb/include/log0log.h:
  Added option to log_checkpoint() to allow one to ignore not critical checkpoints during the time checkpoints are disabled.
storage/xtradb/log/log0log.c:
  Added code to allow one to disable checkpoints during a FLUSH TABLES ... DISABLE CHECKPOINT
  This was done by adding a new argument to log_checkpoint() which tells us when the checkpoint is called by srv_master_thread (which are safe to ignore)
storage/xtradb/srv/srv0srv.c:
  Tell log_checkpoint() that checkpoints from srv_master_thread() are safe to ignore (will just delay recovery time a bit).

The function test_quick_select by mistake did not update the value
of table->quick_condition_rows for index intersection scans though
the specification explicitly required to do so from any table access
plan once the plan provided a better upper bound for the number of
rows selected from the table. It resulted in a bogus, usually very
big number saved as the cost of the table access. This, in its turn,
in many cases forced the optimizer to make a bad choice of the
execution plan for join queries.

Both these two bugs happened due to the following problem.
When a view column is referenced in the query an Item_direct_view_ref
object is created that is refers to the Item_field for the column.
All references to the same view column refer to the same Item_field.
Different references can belong to different AND/OR levels and,
as a result, can be included in different Item_equal object.
These Item_equal objects may include different constant objects.
If these constant objects are substituted for the Item_field created
for a view column we have a conflict situation when the second
substitution annuls the first substitution. This leads to
wrong result sets returned by the query. Bug #724942 demonstrates
such an erroneous behaviour.
Test case of the bug #717577 produces wrong result sets because best
equal fields of the multiple equalities built for different OR levels
of the WHERE condition differs. The subsitution for the best equal field
in the second OR branch overwrites the the substitution made for the
first branch.

To avoid such conflicts we have to substitute for the references
to the view columns rather than for the underlying field items.
To make such substitutions possible we have to include into
multiple equalities references to view columns rather than 
field items created for such columns.

This patch modifies the Item_equal class to include references
to view columns into multiple equality objects. It also performs
a clean up of the class methods and adds more comments. The methods
of the Item_direct_view_ref class that assist substitutions for
references to view columns has been also added by this patch.

In some cases the field max_part_no of the SEL_ARG structure
was not initialized. That triggered a Valgrind complain.

-fimplicit-termplates must be in CXXFLAGS not in handlersocket_la_CXXFLAGS.
otehrwise automake puts it in the command line too early to override
global -fno-implicit-templates

The problem was that connection con5, which is supposed to be the leader for
the third group, could if timing was bad end up as participant in the second
group, causing the test to fail.

Fixed by ensuring that group 2 is running before starting the transaction
for group 3.

LPBUG 756966 is solved.

 - MWL#116 Group commit
 - MWL#136 Enhancements for START TRANSACTION WITH CONSISTENT SNAPSHOT
 - MWL#47 Annotate_rows_log_event
 - MWL#163 innodb_release_locks_early
 - Percona patch enhancing row-based replication for tables with no primary key

- Let advance_sj_state() save the value of JOIN::cur_dups_producing_tables
  in POSITION::prefix_dups_producing_tables, and restore_sj_state() restore
  it. 

Also implement the InnoDB changes for group commit into innodb_plugin.

hold the latch across the 2-phase commit, and it is already released at
start of prepare (if not before).

Rename trx->active_trans to active_flag; since we changed the semantics of
the field, renaming should help prevent silent merge errors.